Phytomyza conyzae

Phytomyza conyzae Kaltenbach, 1859

mine

Upper surface corridor, often following the midrib for some distance. Frequently the very first part of the mine is lower-surface, and sometimes the entire mine remains at the lower surface. The corridor is wide from the start, with irregular sides. Frass initially in two rows of fine grains; further on the grains become larger and more irregular, sometimes forming pearl chains, and are dispersed less regularly. Pupation takes place either outside or within the mine. When the larva has left the mine a semicircular exit slit is made. When the puparium is formed within the mine the spiracula do not penetrate the epidermis, and an irregular semicircular opening is made in the epidermis in front of the puparium (lower picture).